Make the walnut crust:

1. Preheat your oven to 350°F. Lightly grease a 9-inch tart pan with a removable bottom.
2. Toast the walnuts: Spread the walnuts on a rimmed baking sheet and toast for 8-10 minutes, until fragrant and lightly golden. Let them cool for a few minutes—this step brings out so much flavor.
3. Make the crust: In a food processor, pulse the toasted walnuts until finely ground (you want the texture of coarse sand, not nut butter). Add the flour, sugar, and salt, and pulse a few more times to combine. Drizzle in the melted butter and pulse until the mixture looks like wet sand and holds together when you squeeze it.
4. Press into the pan: Dump the walnut mixture into your prepared tart pan. Using your fingers (or the bottom of a measuring cup), press it firmly and evenly into the bottom and up the sides of the pan. Make sure it’s compact—this prevents it from crumbling later.
5. Bake: Bake for 15-18 minutes, until the crust is golden and smells nutty. If it puffs up at all, gently press it back down with the back of a spoon while it’s still hot. Let it cool completely on a wire rack.

Make the chocolate date filling:

1. Heat the cream: In a small saucepan, heat the cream over medium heat until it just starts to simmer—you’ll see little bubbles around the edges. Don’t let it boil.
2. Make the ganache: Place the chopped chocolate, butter, vanilla, and salt in a heatproof bowl. Pour the hot cream over the chocolate and let it sit for 2 minutes without touching it. Then whisk gently until completely smooth and glossy. If you have any stubborn chocolate pieces, you can set the bowl over a pot of barely simmering water and stir until smooth.
3. Add the dates: Fold the chopped dates into the ganache, distributing them evenly.
4. Fill the tart: Pour the ganache into the cooled walnut crust, spreading it into an even layer. Tap the pan gently on the counter a few times to release any air bubbles. Immediately sprinkle the top with flaky salt—don’t be shy, you want to see those crystals.
5. Chill: Refrigerate for at least 3 hours, or until the ganache is set but still has a slight give when you press it gently. For clean slices, I usually let it chill overnight.

Serve:

1. Remove the tart from the pan (run a thin knife around the edges first if needed, then push up from the bottom). Slice with a hot, dry knife (run it under hot water and wipe dry between cuts). Serve with a dollop of lightly sweetened whipped cream if you want to balance the intensity of the chocolate.